Air separator



Align 1932- T. J. STURTEVANT L 1 AIR SEPARATOR Filed June5, 1930 2 Sheets-Sheet 1 Im ENmR ATTQRNEY 5, 93 T. J. STURTEVANT L p 7 AIR SEPARATOR Filed June 5, 1930 2 Sheets-Sheet 2 INVENTORJ BY A I ATTORNEY at her over into the Patented Aug. 16, 1932 'r'rs tenses I ATENT- oF 'FICE.

THOMAS J.STURTEVANT, OF WELLESLEY, MASSACHUSETTS, ASSIGNOR TO STURTEVANT MILL COMPANY, OF BOSTON, MASSACHUSETTS, A CORlORATION OF MASSACHUSETTS AIR. sErAaAroR Application filed. June 5,

course passes through an inlet opening be tween the upper and lower shells forming the casing of the separating chamber. The materials to be graded are fed through a hopper into the separating chamber and are received by a rotary distributor-which throws the materials out across the rising air current under the influence of centrifugal force. The lighter particles are carried upward by a the air current out of the separating chamsettling chamber where they gravitate downward and are delivered therefrom, while the heavier particles gravitate downward through the air current in a the separating chamber and are delivered therefrom.

Heretofore, the lnlet opening has been pro-- vided with a series of spaced vanes'for the purpose of preventing coarser particles whirling in the separating chamber, from escaping through the opening into the settling chamber. It hasfbeen found that the centrifugal efifect of the air' whirling in the separating chamber carries heavier particles out to the vanes, and as they gravitate downward past and adjacent to the vanes they concentrate and tend to form a curtain'or barrier. The air whirling in the settling chamber and passing through the spaces between the vanes into the separating chamber, will carry some fines with 1t, and on entering the separating chamber, they will meet the curtain formed by the heavierparticles and some will be carried downward therewith, whereas efiiciency dictates that these lighter particles should be free to pass up in the separating chamber and over again into the settllng chamber. 3

A purpose of the present invention is to:

. provide means for opposing and checking the whirl of the air in the zone in the separating 1930. Serial No. 459,330.

chamber adjacent to the vanes. This will reduce the centrifugal force and prevent congestion of heavier particles in said zone. a consequence a materiallylarger percentage of the fines entering the separating chamber through the passages between the vanes will be free to rise in said chamber and pass over into the settling chamber. The character of the invention may be best understood by reference to the following de scription of an embodiment thereof shown in the accompanying drawings, wherein:

Fig. 1 is a vertical longitudinal section through an air separator embodying the invention; v

Fig. 2 on an enlarged scale is a horizontal section through a portion "of the separator;. Fig. 3 on an enlarged scale is a sectional detail showing one of the vanes, its pivotal mocpnting, andmeans for adjusting the same; an Fig. 4 on an enlarged scale is a plan showing three portions ofone of the vanes, a'portion of the ring to which it is pivotally connected, and a portion of the ring for adjusting the vane. I I

Referring to the drawings, the separator shown therein as one good embodiment of the invention comprises an outer casing l'con sisting of a drum. 3 having a head 5at the upper'end thereofand a cone 7 atthelower end thereof terminating in a discharge spout 9. This outer casing is provided with brackets 11 adapted to rest upon and be secured to suitable supports. 1

WVithin and spaced from the outer casing is an inner casing 21 comprising a drum 23 having ahead 25 .at the upper end thereof with an outlet opening 27 therein, and a conical shell 29 at the lower end thereof, said drum and shell being provided respectively with angle iron stiffening ribs 31 and 33. This inner casing is supported from the outer casing by triangular brackets 35 having their backs'welded or. boltedto the inner casing drum 23, and their apexes welded to the outer casing drum 3. The construction is such thatthese brackets will effectively support the inner casing from the outer casing, and yet oifer downward in the settling chamber adjacent the inner surface of the drum 3.

- Beneath and spaced from the lower shell 29 is a conical shell 37 communicating with a discharge spout 39 which extends laterally through an opening in the cone 7 of the outer casing. The conical shell37 is supported on the outer cone 7 by webs 41 secured to angle bars 43 secured to the shell and cone.

In the inner casing 21 is the separating chamber 45 and between the inner and outer casings is the settling chamber 47. The space 49 between the upper and lower shells of the inner casing serves as an inlet opening for the passage of air from the settling chamber into the separating chamber. Located at this space is a series of vanes 51, each having a vertical body 53 ig. with a flat outer ortion anda curved inner portion 55. Pro-- ecting transversely from the upper edge of the body 53 is a flange 57 having a hole 59 and. a notch 61therein.

A ring 63 is welded to the lower edge of theshell 29 and the lower ends of the ribs'33.

. The vanes depend from this ring, and are pivotally connected thereto by bolts 67 entered through the vane flange holes 59 and registering holes inthe ri'ng63. WVithin each of the vane flange holes is a split spring washer 67 a, thicker than the flange, and. confined between t-he ring 63 and a plate washer 676 on the bolt, so that when the nut of the bolt. is set up the vane flange will not be pinched and will be free to receive rotative adjustment. The-vanes have an overlapped or shingled-like arrangement, and extend down within the lower conical shell 37 with free ends asubstantial distance beneath the upper edge of said shell. The edge of the shell is left free, and material cannot collect thereon to obstruct the inlet opening 49.

To adjust the vanes, in the present instance, an adjusting ring 71 is provided,. encircling the fixed ring. 63 carrying. the vanes, and resting upon the. flanges 57 of the vanes.v The ring is pivotally connected to the vane flanges by pintles in-the formiof rivets 73 which project through holes in the ring and. the notches 61. of the vane-flanges.

A rod 75 has an eye 77 at one end thereof receiving. a stud 79 secured to the adjusting ring 71, the eyebeing prevented from escaping from the stud. by a cotter pin 81. The opposite end of the rod, 75 projects into a bracket 83 having a boss 85, and acollar 87 secured to the outer casing. A hand wheel 89 has a hub 91 provided with a circumferential groove received'by a herein a two-part plate 93secured to the boss 83,, the construction being such that the hand wheel may rotate,.but not move axially. The rod 75-has a portion 95 threaded into the hand wheel hub 91. The adjusting ring 71 is spaced somewhat from the vane carrying ring. Secured to the latter at suitable intervals are guide members 97 having outer ends engaged by the inner edge of the adjusting ring. When it is desired to adjust the vanes to vary their angularity and the spaces between them, the hand wheel 89 is grasped and rotated, thereby moving the rod 75 longitudinally in the hand wheel hub 91 and moving the adjustingring circumferentially.

To vary the opening 27 referred to, in the head of the inner casing, a valve may be provided comprising a series of overlapped plates 101 secured to radial bars 103 which extend through and beyond the outer casing where they are accessible for adjustment to vary the size of the opening. This valve may be similar to that disclosed in Letters Patent No. 1,615,558, granted to me January 25, 1927, and therefore, it is unnecessary to show and described the same in detail therein.

The materials to be graded are conducted into the separating chamber by the intake neck 105 and the conical hopper 111.

At the top of the separator are channels 121 supporting a housing 123 containing bearings in the upper and lower ends 125 and 127 thereof. Journalled in said bearings is a vertical shaft 129, said shaft being rotated by a bevel gear 131 fast thereon meshing with a bevel pinion 133 on a. horizontal shaft 135 journalled in a bearing carried by the housing and an outer bearing 137 carried by a transverse channel on the channels 121. At the outer end of the shaft is a pulley which may be driven by any suitable source of power. The housing has a neck 139 which projects down into the hopper 111'. The shaft 129- projects down beyond the hopper into the separating chamber, and carries a rotary distributor 143. Projecting up from the rotary distributor are posts 145 carrying a baffle plate 147.

The fan for causing the air to circulate through the separating and settling chambers and the inlet and outlet openings comprises a conical shell hub 155 having aflange 157 at the lower end thereof mounted on and secured to the posts 145. This hub is spaced from the hopper 111 and extends from the separating chamber through the outlet opening 27 up into'the chamber 159 between the heads of the inner and outer casings. Secured to the hub are plates 161 carrying blades 163.

The provision of the curved vanes in the path ofthe returning air is important in promoting efliciency of classification. They can be adjusted so that their curved margins will oppose the whirl of the air in the zone in the separating chamber adjacent to the blades and reduce the centrifugal force and consequent congestion of heavier particles in said zone. Therefore a materially larger percentage of fines. entering the separating chamber will be free to ass over into the settling chamber,

The pivots 67 for the vanes are located intermediate the inner and outer edges of their flanges 57 (Figs. 3 and 4), the distance of the inner edge of each flange from the pivot beingconsiderably less than the distance of the outer edge therefrom. The vanes may be readily adjusted to vary the area of the inlet opening.

Under certain conditions it may be desirable to position the vanes so that they will promote whirl of the air current in the separating chamber, and under still other conditions it may be desirable to set the vanes in a substantially neutral position where they will neither oppose nor promote whirl of the air current in the separating chamber.

The whirl of the air is important to maintain, as it tends to prevent fines from passing from the settling chamber through the passages between the vanes into the separating chamber. The arrangement of the vanes and the passages is such that they always promote whirl of the air in the settling cham her, but at the same time the vanes may be set so that their curved portions may oppose whirl of the air locally in the separating chamber.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is:

1. An air separator for grading materials comprising, in combination, separating and settling chambers having inlet and outlet openings between them, means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a series of spaced vanes having portions curved toward the center of the separating chamber for opposing whirl of the air in the zone in the separating chamber adjacent to the vanes.

2. An air separator for grading materials comprising, in combination, separating and settling chambers having inlet and outlet openings between them,means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a series of spaced vanes having portions curved toward the center of the separating chamber, said vanes being adjustable to oppose or promote whirl of air to said vanes.

3. An air separator for grading materials comprising, in combination, separating and settling chambers having inlet and outlet openings between them, means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a series of spaced vanes having flat outer portions and curved inner portions,

said vanes being adjustable to oppose or propositions where they neither substantiallyoppose or promote whirl of the air in said Zone. 4. An airiseparator for. grading materials comprising, in combination, separating and settling chambers having inlet and outlet openings between them,'1neans to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, a series of spaced vanes having curved inner portions, a support, a flange on each vane, and means pivotally connecting the vanes with the support through said flanges, the pivot point of each vane being between the inner and outer edges of its flange and a substantial distance from the outer edge.

v 5. An air separator for grading materials Y comprising, in combination, separating and settling chambers having inlet and outlet openings betweenthem, means to cause air to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a series of spaced vanes having curved inner portions, and flanges projecting from and transversely to the bodies of the vanes, a ring supporting the vanes, means pivotally connecting the vane flanges to said ring, a ring encircling the supporting ring and pivotally connected to the vane flanges, and means accessible eXteriorly of the separator for mov ing the encircling ring to adjust the vanes to or from air whirl opposing positions.

6. An air separator for grading materials comprising, in combination, separating'and settling chambers having inlet and outlet openings between them, means to cause air currents to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a series of spaced vanes arranged to promote whirl of the air in the settling chamber, each vane having a portion curving into the path of said air currents within the separating chamber for locally opposing whirl of the air in the separating chamber.

7. An air separator for grading materials comprising, in combination, separating and settling chambers having inlet and outlet openings between them, means to cause air currents to circulate and whirl through said chambers and openings and move up in the separating chamber and down in the settling chamber, and a plurality of vanes at said inlet opening, the outer margins of said vanes directed toward the settling chamber being substantially planate and extending in said inlet opening at an angle to promote the whirl of air currents in the settling chamber, and the inner margins of said vanes directed toiii Ward the separating chamber heing bent relatively to said planate outer margins into the. path of the whirling air currents emerging from said vanes and entering the separating chamber whereby the: centrifugal force of said air currents is locally reduced Withinthe separating chamber and the passage of fines up in the separating chamber is promoted 8. An air separator for grading materials comprising, in combination, a. separating chamber and an oute settling chamber having inlet and outlet openings between them, means to cause air currents to circulate and whirl through said chambers and openings and move up in the separatin chamber and down in the settling chamber, and a plural-v ity of vanes at the inlet opening each having an outer portion presented at a neutral angle to the path 01" the-air currents WVlllI'ling in the settling chamber and each having an inner portion extending Within the separating chamber and bent into and across the path of the air currents entering the'separating chamber to oppose and reduce the Whirl of the air currents locally in the separating chamber.

THOMAS J. STURTEVANT. 

